struct timeval, 시간 측정

gcc 3.4.5 (mingw), Windows XP

invalid-file

#include <stdio.h>

#include <sys/time.h>    //    may be different according to Platform

struct timeval calcConsumedTime(struct timeval z_stStartTime, struct timeval z_stEndTime)

{

    struct timeval    z_stConsumedTime;

    z_stConsumedTime.tv_sec = z_stEndTime.tv_sec - z_stStartTime.tv_sec;

    z_stConsumedTime.tv_usec = z_stEndTime.tv_usec - z_stStartTime.tv_usec;

    if ( z_stConsumedTime.tv_usec < 0 )

    {

        z_stConsumedTime.tv_sec -= 1;

        z_stConsumedTime.tv_usec = (z_stEndTime.tv_usec - z_stStartTime.tv_usec + 1000000);

    }

    return z_stConsumedTime;

}    //    end of function calcConsumedTime()

int main()

{

    int    i;

    struct timeval z_stStartTime, z_stEndTime, z_stConsumedTime;

    //    write start time

    if ( gettimeofday(&z_stStartTime, (void*)NULL) == -1 )

    {

        printf("time variable initialization error\n");

        return -1;

    }

    for ( i = 0; i < 10000000; ++i )

        ;

    //    write end time

    if ( gettimeofday(&z_stEndTime, (void*)NULL) == -1 )

    {

        printf("time variable initialization error\n");

        return -1;

    }

    printf("function timeCheck() took %ld.%03ld seconds\n", z_stStartTime.tv_sec,

            z_stStartTime.tv_usec / 1000);    //    pay attention to divide 'tv_usec' by 1000

    printf("function timeCheck() took %ld.%03ld seconds\n", z_stEndTime.tv_sec,

            z_stEndTime.tv_usec / 1000);    //    pay attention to divide 'tv_usec' by 1000

    z_stConsumedTime = calcConsumedTime(z_stStartTime, z_stEndTime);

    printf("function timeCheck() took %ld.%03ld seconds\n", z_stConsumedTime.tv_sec,

            z_stConsumedTime.tv_usec / 1000);    //    pay attention to divide 'tv_usec' by 1000

    return 0;

}    //    end of function main()